How to get a transparent shader equal to the Maya`s x-ray shader?
First option - Cycles in Rendered view.



You can mix Transparent with Diffuse or in this case Emission shader by Layer Weight > Facing. Additionally you can add Color Ramp to have even more control over Facing falloff.

This material is added to the monkey mesh.



Second option - X-Ray in any other view.



This option will allow you to see chosen object trough everything else in the scene. You will need to check X-Ray under Object tab > Display section > X-Ray.



This option is turned on for the sphere mesh.